DESCRIPTION: One of the major features governing early animal development is the stability and translatability of specific maternal messenger RNA molecules, which in turn is controlled by cytoplasmic polyadenylation of these molecules. This strong proposal, clearly written by an accomplished investigator, focuses on several aspects of this phenomenon in the Xenopus system, including (1) the RNA binding protein CPEB that is essential for the poly(A) addition, its domain structure, and its regulation by phosphorylation, (2) the interactions of CPEB with other proteins of the cytoplasmic polyadenylation apparatus, (3) the cloning of as-yet-unidentified proteins associated with steps in the process from poly(A) addition to translational initiation, and (4) the mechanism for how cytoplasmic polyadenylation may be coupled to translation. Progress since the last competing renewal has been substantial, though its course has changed somewhat from that previously proposed. Specifically, the goals to clone and study the 82 kD and 19 kD (Sm) proteins were not pursued, presumably due to the intriguing and important alternative directions presented by the cloning and characterization of the 58 kD protein, designated CPEB (for cytoplasmic polyadenylation element binding protein), and the involvement of 5' cap methylation.